Merocyanine dyes and intermediates



United States Patent 2,856,404 MEROCYANINE DYES AND INTERMEDIATES LeslieG. S. Brooker and Donald W. Heseltine, Rochester, N. Y., assignors toEastman Kodak Company, Rochester, N. Y., a corporation of New Jersey 1No Drawing. Application June 20, 1956 Serial No. 592,507

8 Claims. (Cl. 260-240) This invention relates to an improved method ofmaking merocyanine dyes, some of which are new compositions of matter,and new intermediates for making these merocyanine dyes. The merocyaninedyes produced according to our invention can be employed in opticallysensitizing photographic silver halide emulsions.

It is, therefore, an object of our invention to provide an improvedmethod for making merocyanine dyes. Another object is to provide certainnew merocyanine dyes. Still another object is to provide newintermediates for making these merocyanine dyes. A further object is toprovide photographic silver halide emulsions sensitized with thesemerocyanine dyes. Other objects will become apparent from aconsideration of the following description and examples.

According to our invention, we provide an improved method for makingmerocyanine dyes by condensing an intermediate selected from thoserepresented by the following general formula:

HaC-

H wherein D represents the atoms necessary to complete a cyclohexenering and Q represents the non-metallic atoms necessary to complete anucleus of the indandione series (e. g., 1,3-diketohydrindene, etc.) ora heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclicring, such as those of the pyrazolone series (.e. g.,-3-methyl-l-phenyl-S-pyrazolone, l-phenylS-pyrazolone,1-(2-benzothiazolyl)-3-methy1r5pyrazolone, etc.), those of theisoxazolone series (e. g., 3-phenyl-5(4H)-isoxazolone,3-methyl-5(4H)-isoxazolone, etc.), those of the oxindole' series, (e.g., 1-alkyl-2,3-dihydro-2-oxindoles, etc.), those of the2,4,6-triketodhexahydropyrimidiue series (e. g., barbituric acid or2-thiobarbituric acid as well as their l-alkyl (e. g., l-methyl,l-ethyl, l-n-propyl,

l-n heptyl, etc.), or 1,3-dialkyl (e. g., 1,3-dimethyl, 1,3- diethyl,1,3-di-n-propyl, 1,3-diisopropyl, 1,3-dicyclohexyl,LB-diQS-methoxyethyl), etc.), or 1,3-diaryl (e. g., 1,3- diphenyl,1,3-di(p-chlor0phenyl), 1,3-di(p-ethoxycarbonylphenyl), etc.), or l-aryl(e. g., 1-pheny1, l-p-chlorophenyl, 1-p-ethoxycarbonylphenyl), etc.) orl-alkyl-S- aryl (e. g., 1-ethyl-3-phenyl, l-n-heptyl-S-phenyl, etc.)derivatives), those of the rhodanine series (i. e., 2-thio-2,4-thiazolidinedione series), such as rhodanine, 3-alkylrhodanines (e.g., 3-ethylrhodanine, 3-allylrhodanine, etc.) or 3-arylrhodanines (e.g., 3-phenylrhodanine, etc.), etc., those of the2(3H)-imidazo[l,2-a]-pyridone series, those of the5,7-dioxo-6,7-dihydro-5-thiazolo-[3,2-a]- pyrimidine. series (e. g.,5,7-dioxo-3-phenyl-6,7-dihydro- 5-thiazolo[3,2-u]pyrimidine, etc.),those of the 2-thio-2,4- oxazolidinedione series (i. e., those of the2-thio-2,4- (3H,5H)-oxazoledione series) (e. g., 3-ethyl-2-thio-,2,4-oxazolidinedione, etc.), those of the thianaphthenone series (e. g.,3(2H)-thianaphthenone, etc.), those of the Z-thio-2,5-thiazolidinedioneseries (i. e., the 2-thio-2,5-

(3H,4H)-thiazoledione series) (e. g., 3-ethyl-2-thio-2,5-thiazolidinedione, etc.), those of the 2,4-thiazolidinedione series (e.g., 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione,3-phenyl-2,4-thiazolidinedione, Sax-naphthyl-2,4-thiazolidinedione,etc.), those of the thiazolidinone series (e. g., 4-thiazolidinone,3-ethyl-4-thiazolidinone, 3-phenyl-4-thiazolidinone,3-a-naphthyl-4-thiazolidinone, etc.), those of the 4-thiazolinone series(e. g., 2- ethylr'nercapto-4-thiazolinone,2-alkylphenylamino-4-thiazolinones, 2-diphenylamino-4-thiazolinone,etc.), those of the 2-imino-2,4-oxazolinone (i. e., pseudohydantoin)series, those of the 2,4-imidazolinedione (hydantoin) series (e. g.,2,4-imidazolinedione, 3-ethyl-2,'4-imidazolinedione,3-phenyl-2,4-imidazolinedione, 3-u-naphthyl- 2,4-imidazolinedione,1,3-diethyl-2,4-imidazolinedione, 1- ethyl-3-a-naphthyl 2,4imidazolinedione, 1,3 diphenyl- 2,4-imidazolinedione, etc.), those ofthe 2-thio-2,4-imidazolinedione (i. e., 2-thiohydantoin) series (e. g.,2-thio- 2,4-imidazoliuedione, 3-ethyl-2-thio-2,4-imidaz0linedione,3-phenyl-2-thio-2,4-imidazolinedione, 3-a-naphthyl-2-thio-2,4-imidaz0linedione, 1,3 diethyl-2-thio-2,4-imidazolinedione,1-ethyl-3-phenyl-2-thio-2,4-imidazolinedione, 1-ethyl-3-a-naphthyl-2-thio 2,4 imidazolinedione,1,3-diphenyl-2-thio-2,4-imidazolinedione, etc.), those of the 5-imidazolinone series (e. g., 2-n-propylmercapto-5-imidazolinone, etc.),etc. (especially a heterocyclic nucleus containing 5 atoms in theheterocyclic ring, 3 of said atoms being carbon atoms, 1 of said atomsbeing a nitrogen atom, and 1 of said atoms being selected from the groupconsisting of a nitrogen atom, an oxygen atom, and a sulfur atom), witha compound selected from those represented by the following generalformula:

wherein R represents an alkyl group (e. g., methyl ethyl, n-propyl,n-butyl, isobutyl, n-amyl, isoamyl, p-methoxyethyl, {3-ethoxyethyl,allyl (i. e., methylvinyl), benzyl (phenylmethyl), p-phenylethyl,carboxymethyl, etc.) (especially alkyl groups containing from 1 to 4carbon atoms), n represents a positive integer of from 1 to 2, Xrepresents an acid radical (e. g., chloride, bromide, iodide,p-toluenesulfonate, benzenesulfonate, ethylsulfate, methylsulfate,etc.), D represents an electronegative radical, such as alkyhnercapto(e. g., methylmercapto, ethylmercaptq; etc.), arylmercapto (e. g.,phenylmercapto, tolylmercapto, etc.), a B-acylanilidovinyl group (e. g.,fl-acetanilidovinyl, fl-benzoylanilidovinyl, etc.), aB-acylanilido-1,3-butadienyl group (e. g., fi-acetanilido-1,3-butadienyl, a-benzoylanilido-1,3-butadienyl, etc.), etc., and Zrepresents the non-metallic atoms necessary to complete a heterocyclicnucleus containing from 5 (n is 1) to 6 (n is 2) atoms in theheterocyclic ring, such as those selected from the group consisting ofthose of the thiazole series (e. g., thiazole, 4-methylthiazole, 4-phenylthiazole, S-methylthiazole, S-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4(2-thienyl)thiazole, etc.),those of the benzothiazole series (e. g., benzothiazole,4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-chlorobenzothiazole,7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole,6-methylbenzothiazole, 5-bromobenzothiazo1e, -bromobenzothiazole,4-phenylbenzothiazole, S-phenylbenzothiazole, 4-methoxybenzothiazole,S-methoxybenzothiazole, ti-methoxybenzothiazole, S-iodobenzothiazole,6-iodobenzothiazole, 4- ethoxybenzothiazole, S-ethoxybenzothiazole,tetrahydrobenzothiazole, 5,G-dimethoxybenzothiazole,5,6-dioxymethylenebenzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, etc.), those of the naphthothiazole series (e. g.,naphtho[l,2-]thiazole, naphtho[2,1]thiaz0le 5-methoxynaphtho[2,1]thiazole, 5 -ethoxynaphtho[2,1] wherein R, Z, n, Dand Q each have the values given thiazole,8-meth0xynaphthoI1,2]thiazole, 7-methoxynaphabove and d represents apositive integer of from 1 to 3. tho[1,2]thiazole, etc.), those of thethianaphtheno- The dyes produced by condensing an intermediate se-7',6,4,5-thiazole series (e. g., 4-methoxythianaphthenolected from thoserepresented by Formula III with those 7,6',4.,5-thiazole, etc.), thoseof the oxazole series (e. g., 5 of Formula II can be represented by thefollowing gen- 4-methyloxazole, S-methyloxazole, 4-phenyloxaz-o1e, 4,5-eral formula:

wherein R, Z, n, d, R R R and Q each have the values given above.

diphenyloxazole, 4-ethy1o'xazole, 4,5-dimethyloxazo1e, 5- phenyloxazole,etc.), those of the benzoxazole series I (e. g., benzoxazole,S-chlor-obenzoxazole, S-methylben- The condensations of theintermediates of Formulas zoxazole, 5 phenylbenzoxazole, 6methylbenzoxazole, I or III with the compounds of Formula II can beacceler- 5,6-dimethylbenzoxazole, 4, 6- dimethylbeuzoxazole, 5- 2 atedby basic condensing agents, such as the trialkylmethoxybenzoxazole,ethoxybenzoxazole, S-chloroamines, (triethylamine, tri-n-propylamine,triisopropylbenzoxazole, '6-methoxybenzoxazole, S-hydroxyb'enzoxamine,trim-butylamine, etc.), N,N-dialkylanilines (e. g., azole,6-hydroxybenzoxazole, etc.), those of the naph- N,N-dimethylaniline,N,N-diethylaniline, etc.), N-alkylthoxazole series (e. g.,naphtho[1,2]oxazole, naphthopiperidines (e. g., N-methylpiperidine,N-ethylpiperidine, [2,l]oxazole, etc.), those of the selenazole series(e. g., etc.), etc. The condensations can be carried out in the4-methylselenazole, 4-phenylselenazole, etc.), those of the presence ofan inert diluent, such as the lower alcohols benzoselenazole series (e.g., benzoselenazole, S-chloro- (e. g., ethanol, n-propanol, isopropanol,n-butanol, etc.), benzoselenazole, S-methoxybenzoselenazole,S-hydroxypyridine, quinoline, 1,4-dioxane, etc. Heat acceleratesbenzoselenazole, tetrahydrobenzoselenazole, etc.), those thecondensations, although temperatures varying from of thenaphthoselenazole series (e. g., naphtho[1,2]selenambient (ca. 25 C.) tothe reflux temperature of the reazole, naphtho[2,1]selenazole, etc.),those of the thiaction mixture can be employed.

az-oline series (e. g., thiazoline, 4-methylthiazoline, etc.), Accordingto our invention, we provide the intermethose of the 2-quinolineseries-(e. g., quinoline, 3-methyldiates represented by Formula I aboveby condensing a quinoline, S-methylquinoline, 7-methylquinoline, 8-ketone selected from those represented by the following methylquinoline,6-chloroquino1ine, 8-chloroquinoline, general formula:

G-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinov line,S-hydroxyquinoline, etc.), those of the 4-quinoline X series (e. g.,quinoline, 6-methoxyquinoline, 7-methyl- H5O C\ quinoline,S-methylquinoline, etc.), those of the l-isoquinoline series (e. g.,isoquinoline, 3,4-dihydroisoquinoline, etc.), those of the3-isoquinoline series (e. g., iso- I quinoline, etc.), those of thebenzimidazole series (e. g., one compound selected from thoserepresented by the 1,3-diethylbenzimidazole,-1-ethyl-3-phenylbenzimidazole, following general formula: etc.), thoseof the 3,3-dialkylindolenine series (e. g., 3,3- VI ,Q\dimethylindolenine, 3,3,5-trimethylindolenine, 3,3,7-tri- Xmethylindolenine, etc.), those of the 2-pyridine series H2O 0:0 ('e. g.,pyridine, S-methylpyridine, etc.), those of the 4 wherein Q-has thevalues given above. Particularlyu'sepyridine series idin m), t fulketones selected from those represented by Formula Particularly usefulintermediates selected from those V above'include those represented ythe57f0110wing "8 represented by Formula I above include those reprefllformula:

wherein D has the values given above with a ketomethylsented by thefollowing general formula: R2 Rs 111 R2 /Rz H C/ \CH 11-0 21:: o HaO-b=0 Hie-o o=6- -b=o Q H H wherein R R and R each have'the values givenabove.

wherein R -represents a hydrogen atom or a carbalkoxyl Typical ketonecompounds selected from those repre group such as 'carbomethoxyl,carbethoxyl, etc. (e. g., sented by Formulas V and VII above includeisophorone, a carbalkoxyl group containing from 2 to 3 carbon3,5-dimethyl-2'cyclohexen-l-one, S-methyI-Z-cyclohexenatoms), R and Reach represents a hydrogen atom or a l-one, 4carbethoxy-3-methyl-Z-cyblohexeh-l-one, etc. lower alkyl group, such asmethyl, ethyl, etc., and Q The condensations of the compounds of FormulaVI has the values given above. with those of Formulas V or VII can beaccelerated by The dyes produced by condensing an intermediate 86-strong basic condensing agents, such as piperidine, dilected from thoserepresented by Formula I above with ethylamine, etc., or by a mixture ofammonium acetate. those of Formula II can be represented by thefollowing and acetic acid. These condensations can be convenientgeneralformula: 1y carried out in an inert diluent, such as chloroform,

diethyl ether, etc.. Heating accelerates. these condensations,temperatures varying from ambient (ca. 25' C.) to the reflux temperatureof the reaction mixture being particularly useful.

The following examples will serve to illustrate more fully the mannerwhereby we practice our invention.

Example 1.3-ethyl-5-(3,5,S-tfimethyl-Z-cyclohexen-J- ylidene)-rhodaninetion was concentrated to 50 ml. and chilled overnight.

The crude crystalline product was filtered off and recrystallized frommethyl alcohol. The yield of purified product was 8.5 g. (15%), M. P.122-3 C.

Example 2.3-methyl-1-phenyl-4-(3,5,5-trimethyl-2-cyclohexen-I-ylidene)-5-pyrazol0ne CH3 CH;

HaC- N 3-methyl-l-phenyl-S-pyrazolone 17.4 g., 1 mol.), isophorone (15g., 1 mol.+l0%) and two drops of piperidine were mixed and heated in anoil bath at ISO-135 C. for four hours. The reaction mixture was thenextracted with 400 ml. of 90l20 C. ligroin. The ligroin solution wasallowed to cool to room temperature and was then decanted from separatedresinous material. After chilling and stirring the desired productseparated from the ligroin solution. The crude product was filtered offand recrystallized from ligroin. The yield of purified product was 14.2g. (48%), M. P. 115-117 C.

Example 3 .1 ,3-diethyl-5 3,5 ,5 -trimethyl-2-cyclohexen- 1 -ylidene)-2-thi0barb iturl'c acid 1,3-diethyl-2-thiobarbituric acid (40 g., 1mol.) and isophorone (30.3 g., 1 mol.+%) were dissolved in chloroform(100 ml.), and ammonium, acetate (2.5 g.) and acetic acid (4 ml.) wereadded. The mixture was heated under reflux for an hour in a systemfitted for continuous removal of water. The reaction mixture was thenWashed with two 100 ml. portions of water and the chloroform removed bydistillation. The residue was recrystallized from methyl alcohol and theyield of purified material was 35.2 g. (55%), M. P. 108-9 C.

6 Example 4.,-3-phenyl-4 (3,5,5-trimethyl-Z-cyclohexen-I- ylidene-5-(4H)-isoxaz0lone OH; CH

Back

| CH: /N

Example 5 .1 2 -benzothiazolyl) -3-mgthyl-4- (3,5 ,5-trimethyl-Z-cyclohexen-I -ylidene) -5-pyrazalone i CH:

1 (2 benzothiazolyl) 3 methyl 5 pyrazolone (7.7 g., 1 mol.) andisophorone (5.1 g., l mol.+10%) were dissolved in chloroform (40 ml.),and ammonium acetate (2 g.) and acetic acid (4 ml.) were added. Themixture was heated under reflux for twenty-four hours in an apparatusdesigned for the continuous removal of water. The chloroform solutionwas washed with two 20 ml. portions of water and the solvent removedunder reduced pressure. The residue was stirred with methyl alcohol (50ml.) and filtered, the solid being discarded. The methyl alcoholicsolution was treated with water (200 ml.) and the precipitated productfiltered off. After recrystallization from methyl alcohol, the yield ofpurified material was 2.8 g. (24%), M. P. 204-5 C. dec.

Example 6.--3-ethyl- -[4(3-methyl-2(3H)-benz0xazolylidene)-1-3-ne0pentylene-Z-butenylidene]rhodaninechilling overnight, the crude dye was filtered ofi, washed with waterand methyl alcohol and dried. The yield of purified dye after tworecrystallizations from pyridine and methyl alcohol was 0.42 g. 41%), M.P. 21mg? C.dec. -f

2-methylmercapto-wnaphthoxazole (2.15 g.,. 1 mol.-l-.-

100%) andmethyl p-toluenesulfonate (2.05. g., 1 moll l- 120%) were mixedand heatedovernight in. anoil' bath at IOU-105 C. The crude quaternarysalt and 3-ethyl-5- (3,5,5 trimethyl 2 cyclohexen 1 ylidene)rhodanine(1.40 g., 1 mol.) were dissolved in pyridine and triethylamine (1.4 ml.,1 mol.+100%) was added. After heating under reflux for a half-hour, thereaction mixture was poured with stirring into methyl alcohol (150 ml.)and chilled overnight. The crude dye was filtered off, washed withmethyl alcohol and dried. The crude dye was purified by boiling withthree 100 ml. portions of methyl alcohol and filtering hot each time.After two recrystallizations from pyridine and methyl alcohol, the yieldof purified dye was 0.73 g. (31% M. P. 25l-2 C. dec.

Example 8.--3 ethyl 5 [4 (1 methyl 2(1H)- naphth[1,2]oxazo lylidene) 1,3neopentylene 2- butenylidene] rhodanz'ne.

2-methylmercapto-B-naphthoxazole (2.15 g., 1 mol.+ 100%) and methylp-toluenesulfonate (2.05 g., 1 mol.+ 120%) were mixed and heated on theoilbath at 100- 105 C. overnight. The crude quaternary salt and 3- ethyl5 (3,5,5 trimethyl 2 -cyclohexen 1 ylidene) rhodanine (1.40 g.,.1mol.)-were dissolved in pyridine ml.) and triethylarnine (1.4 ml., 1.mol.+100%) was added. After the reaction mixture was heated under refluxfor a half-hour, it was poured into methyl alcohol (150 ml.) withstirring. After chilling overnight, the crude dye"was'filtered oflf',boiled with three 100 ml. portions of methyl alcohol, filtered anddried. After two recrystallizations from pyridine and methyl alcohol,the yield of purified dye was'0.37 g. (16%), M. P. 2645 C. dec. Example9.--3-ethyl-5-[4-(l-methyl 2(1H)-ntrptho[1,2]

selenazolylidene) 1,3 neopentylene Z-butenylidene] rhodanine3-e'thyl'5-(3,5,5-trimethyl -'2 cyclohexen 1 ylidene) rhodanine (0.70g., 1 mol.) and l-methyl-Z-methyl'rnercaptonaphtho 1,2] selenazoliump-toluenesulfonate (1.20" gt, 1 moll+10%)' were dissolved in pyridine"(151111.), and triethylam'ine (0.7 ml., 1 mo1.+100%-) was added.

. 8 The reaction mixture was heated under reflux for a half-hour andwas; then poured into methyl alcohol (150 11111). After chilling"overnight, the crude dye was filtered off, washed with methyl alcoholand dried. After two recrystallizations from pyridine and methyl alcoholthe yield" of purified dye was 0.65 g. (49%), M. P. 234-5" C. dec.

Exam p le 1 0: 3 methyl 4-[4 (3 methyl-2 (3H)-benz0xazolylidene) 1,3neopentylene 2 butenylidene] 1- phenyl-S-pyrwzolone N H I,

l CH3 CH2 3-methyl -l-phenyl4 (3,5,5 trimethyl 2 cyclohexe'n-1-ylidene)'- 5 -pyra'zolon'e (1.47 g., 1 mol.), 3-methyl-2-methylmercaptobenzoxazolium p-toluenesulfonate (5.26 g., 1 mol.+200% andtriethylaniine (2.1 ml., 1 H10l2+ 200%) were dissolved in pyridine ('15ml.) and the mix CH CH2 1, 3' 'diethy1-5-(3 ,5,S-trimethyl-2-cyclohexen-1-y1idenei)- Z-thiobarbiturio acid (1.54 g., 1mol.) and 3-methyl-2- methylmercaptobenzothiazolium p-toluene'sulfo'nate(3.67" g.,. 1 m'ol.+1'00%) were dissolved in pyridine (15 ml.) andtriethyla'mine (1.4 ml., 1 mol.+-100%) was added.

The reaction mixture was heated under reflux for. ten:

minutes and the crude dye was then precipitated by the addition ofmethylalcohol (100 ml.). overnight, the dye was filtered off, washedwith methyl alcohol and dried. After two recrystallizations frompyridine and methyl alcohol, the yield of purified dye was 1.82 g. M. P.237-8 C.

Example 12.-4-[4-(3-ethyl-2(3H)-benzothiazolylidene)-1,3-ne0pentylene-2+butenylidene] 3 phenyl 5(4H)- isoxazalone CH| CH3-phenyl-4-(3,5,S-trimethyl-Z-cyclohexen 1 ylidene)- 5 ('4H)-isoxazolone(1.41 g., 1 mol.), 3-ethyl-2-ethylmercaptobenzothiazolium ethylsulfate(3.32 g., 1 mol.+- and triethylamine (1.4 ml., 1 mol.+1.00%) weredissolved in. pyridine (.10 ml.) and heated under reflux for tenminutes; The crude dye was then precip-- After chilling Example 13.-4 [6(3 ethyl 2 (3H) benzothiazolylidene) 1,3 neopentylene 2,4hexadienylidenel-3- phenyl-5 (4H) -isoxazolone3-phenyl-4-(3,5,5-trimethyl-2-cyclohexen 1 ylidene)- 5(4H)-isoxazolone(1.41 g., 1 mol.), Z-ti-acetanilidovinyl-3-ethylbenzothiazolium iodide(2.25 g., 1 mol.) and triethylamine (1.4 ml., 1 mol.+l%) were dissolvedin pyridine (10 ml.) and heated under reflux for ten minutes. Thereaction mixture was poured into a beaker,

100 ml. of methyl alcohol added with stirring and the mixture chilledovernight. The crude dye was then filtered off, washed with methylalcohol and dried. After two recrystallizations from pyridine and methylalcohol, the yield of purified dye was 1.59 g. (68%), M. P. 232-3 C.dec.

Example 14.4-[8-3-ethyl-2(3H) benzothiazolylidene)-1,3-ne0pentylene2,4,6 oczatrienylidene] 3 phenyl- (4H) -is0xazoloneExample 15.1-(2 benzothiazolyl) 3-methyl 4-[4-(3- methyl-2 (3H)-benzoxazolylidene) 1,3 neopentylene- Z-butenylidene] -5-pyrazol0ne CH3CH3 He CH5 Z-methylmercaptobenzoxazole (1.65 g., 1 mol.+400%) and methylp-toluenesulfonate (1.86 g., 1 mol.+400%) were mixed and heated toreflux over a free flame and then allowed to cool slowly to roomtemperature. 1 (2 benzothiazolyl) 3 methyl 4 (3,5,5 trimethyl-2-cyclohexen-1-ylidene)-5-pyrazolone (0.71 g., 1 mol.), triethylamine(1.4 ml., 1 mol.+400%) and pyridine ml.) were then added and thereaction mixture heated '10 under reflux for ten minutes. The crude dyewas precip itated by the addition of methyl alcohol ml.), filtered fromthe reaction mixture, washed with methyl alcohol and dried. After tworecrystallizations from pyridine and methyl alcohol, the yield ofpurified. dye was 0.24 g. (25%), M. P. 310-11 C. dec.

In a manner similar to that illustrated in the above examples, other newintermediates and merocyanine dyes can be prepared. For example, theintermediate represented by the following formula:

can be prepared by condensing l-methyl-Z-thiobarbituric acid with4-carbethoxy-3-methyl-2-cyclo hexen-l-one.

All the dyes of our invention are particularly useful in manufacturingphotographic, silver halide emulsions, serving to alter the sensitivitythereof. Sensitization by means of our new dyes is, of course, directedprimarily to the ordinarily employed, gelatino-silver-halide,developing-out emulsions. The dyes are advantageously incorporated inthe washed, finished emulsion and should, of course, be uniformlydistributed throughout the emulsion. In the preparation of photographicemulsions containing our new dyes, it is only necessary to disperse thedyes in the emulsions. The methods of incorporating dyes in emulsion aresimple and well known to those skilled in the art of emulsion making. Itis convenient to add the dyes from solutions in appropriate solvents.The solvent must, of course, be compatible with the emulsion andsubstantially free from any deleterious effect on the light-sensitivematerials. Pyridine has proven satisfactory as a solvent for themajority of our new dyes.

The concentration of our new dyes in the emulsion can vary widely, i.e., from about 5 to about 100 mgs. per liter of flowable emulsion. Theconcentration of the dye will vary according to the type oflight-sensitive material in the emulsion and according to the effectsdesired. The suitable and most economical concentration for any givenemulsion will be apparent to those skilled in the art upon making theordinary tests and ,observations customarily used in the art of emulsionmaking.

To prepare a gelatino-silver-halide emulsion sensitized with one of ournew dyes, the following procedure is satisfactory: A quantity of the dyeis dissolved in pyridine or other suitable solvent and a volume of thissolution (which may be diluted with methanol) containing from 5 to 100mgs. of dye is slowly added to about 1000 cc. of agelatino-silver-halideemulsion, with stirring. Stirring is continueduntil the dye is uniformly distributed throughout the emulsion. Withmost of our new dyes, 10 to 20 mgs. of dye per liter of emulsionsuflices to produce the maximum sensitizing effect with the ordinarygelatino-silver-bromide (including bromiodide) emulsions. Withfine-grain emulsions, which include most of the ordinarily employed.gelatino-silverchloride emulsions, somewhat larger concentrations of dyemay be necessary to secure the optimum sensitizing effect.

The above statements, are only illustrative and are not to be understoodas limiting our invention in any sense, as it will be apparent that ournew dyes can be incorporated by other methods in many of thephotographic silver halide emulsions customarily employed in the art.For instance, the dyes can be incorporated by bathing a plate or fihnupon which an emulsion has been coated, in the solution of the dye, inan appropriate solvent. Bathing methods, however, are not to bepreferred ordinarily.

11 Photographic silver halide emulsions which. can advantageously besensitized by means of the new dyes of our invention comprise thecustomarily employed gelatinosilver-chloride, gelatino-silverchlorobromide, gelatinosilver-bromide, and gelatino-silver-bromiodidedevelopingout emulsions.

Photographic silver halide emulsions, such as those listed above,containing the sensitizing dyes of our invention can also contain suchaddendaas chemical sensitizers, e. g., sulfur sensitizers (e. g., allylthiocarbamide, thio urea, allylisothiocyanate, cystine, etc.), variousgold compounds (e. g., potassium chloroaurate, auric trichloride, etc.)(see U. S. Patents 2,540,085; 2,597,856 and 2,597,915, various palladiumcompounds, such as palladium chloride (U. S. 2,540,086), potassiumchloropalladate (U. S. 2,598,079), etc., or mixtures of suchsensitizers; anti-foggants, such as ammonium chloroplatinate (U. S.2,566,245), ammonium chloroplatinite (U. S. 2,566,263), benzotriazole,nitrobenzimidazole, S-nitroindazole, benzidine, mercaptans, etc. (seeMees-- The Theory of the Photographic Process, MacMillan Pub, 1942, page460), or mixtures thereof; hardeners} such as formaldehyde (U. S.1,763,533), chrome alum (U. S. 1,763,533), glyoxal (U. S. 1,870,354),dibromacrolein (Br. 406,750), etc.; color couplers, such as thosedescribed in U. S. Patent 2,423,730, Spence and Carroll U. S. Patent2,640,776, etc; or mixtures of such addenda. Dispersing agents for colorcouplers, such as those set forth in U. S; Patents 2,322,027 and2,304,940, can also be employed in the above-described emulsions.

In the manner described above, a number of the dyes of our inventionrepresented by Formulas IV or IVa above were separately incorporated inan ordinary gelatino-silver-bromiodide emulsion, the dyes beingthoroughly incorporated in the emulsions by stirring. After a shortdigestion, the-emulsions were coated onto ordinary cellulose acetatefilm supports and the coatings exposed in a spectrograph andsensitometer and then developed in the usual way. The sensitizing rangeand maximum absorption for each of the dyes are indicated in thefollowing table.

What we claim as our invention and desire secured by Letters Patent ofthe United States is:

l. A process for makingpolymethine dyes comprising condensing in thepresence of a basic condensing agent an intermediate selected from thoserepresented by the following general formula:

wherein R represents a member selected from the group consisting of ahydrogen atom. and a carbalkoxyl group containing from 2v to 3 carbonatoms, R2 and R3 each represents a member selected from the groupconsisting of a hydrogen atom and. a. lower alkyl group, and Qrepresents the non-metallic atoms necessary to complete a nucleusselected from the group consisting of anindan':

dione nucleus, a pyrazolone nucleus, an isoxazolone:

nucleus, an oxindole nucleus, at 2,4,6-triketohexahydropyrimidinenucleus, a 2-thio-2,4,6-triketohexahydropyrimidine nucleus, a rhodaninenucleus, a 2(3H')-imidazo- [1,2-alpyridone nucleus, a5,7-dioXo-6,7-dihydro-5-thia Z010 [3,2-alpyrimidine nucleus, a2-thio-2,4-oxazolidine1-- dione nucleus, a thianaphthenone nucleus, a-2-.thio?2,5- thiazolidinedione nucleus, a 2,4-thiazolidinedionenucleus,a thiazolidinone nucleus, a 4-thiazolinone nucleus, a 2-imino-2,4-oxazolinone nucleus, a 2,4-imidazolinedione nucleus, a2-thio-2,4-imidazolinedione nucleus, and a 5- imidazolinone nucleus,with a compound selected from those represented by the following generalformula:

wherein R represents an alkyl group containing from 1 to 8 carbon atoms,11 represents a positive integer of from 1 to 2, X represents an acidradical, D represents a member selected from the group consisting of analkylmercapto group containing from 1 to 2 carbon atoms, anaryl':

mercapto group containing from 6 to 7 carbon atoms, a-B-acylanilidovinyl group wherein the acyl radical contains from 2 to 7carbon atoms, and a B-acylanilido-LS- butadienyl group wherein the acylradical contains from 2 to 7 atoms, and Z represents the non-metallicatoms necessary to complete a heterocyclic nucleus selected fromthegroupconsisting of a thiazole nucleus, 21 benzothiazole nucleus, anaphthothiazole nucleus, at thianaph theno-7',6',4,5-thiazole nucleus,an oXazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, aselenazole nucleus, a benzoselenazole nucleus, at naphthoselenazolenucleus, a thiazoline nucleus, a 2-quinoline nucleus, 8. 4-quinolinenucleus, a l-isoquinoline nucleus, a henzimidazolc nucleus, a3,3-clialkylindolenine nucleus,.a 2ipyridine nucleus, and a 4-pyridinenucleus.

2. A process as defined in claim 1 wherein the basic condensing agent isa trialkylamine.

3. A process as defined in claim 2 wherein the tri alkylamine istriethylamine.

4. An intermediate useful in the preparation of polyfollowing generalformula:

wherein R represents a member selected from the group consisting of ahydrogen atom and a carbalkoxyl group containing from 2 to 3 carbonatoms, R and R each represents a member selected from the groupconsisting of a hydrogen atom and a lower alkyl group, and Q representsthe non-metallic atoms necessary to complete a nucleus selected from thegroup consisting of an indandione nucleus, a pyrazolone nucleus, anisoxazolone nucleus, an oxindole nucleus, a2,4,6-triketohexahydropyrimidine nucleus, 212-thio-2,4,6-triketohexahydropyrimidine nucleus, 'a rhodanine nucleus, a2(3H)-imidazo[l, Z-allpyridone nucleus, a5,7-dioxo-6,7-dihydro-5-thiazolo ['3,2-a]pyrimidine nucleus, a2-thio-2,4-oxazolidinedi-one nucleus, a thianaphthenone nucleus, a2-thio-2,5-thiazolidinedione nucleus, a 2,4-thiazolidinedione nucleus,8. thiazolidinone nucleus, a 4-thiazolinone nucleus, a 2-imino-2,4-oxazolinone nucleus, a 2,4-imidazolinedi0ne nucleus, a2-thio-2,4-imidazolinedione nucleus", anda. 5'.- i'midazoli'nonenucleus.

13 14 5. The compound represented by the following formula: O

CH3 CH3 HzC OHQ I l--1| -CzH A R W s H2? (3H1 -N\ s 8. The compoundrepresented by the following foro C--N mnla: H g g H 01%; CH;

2 a /Q( (I) 11,0 cm d--N-om 6. A compound represented by the followingformula: H1041} l;

CH3 011 I \O/ 0 CH3 References Cited in the file of this patent E UNITEDSTATES PATENTS K 2,465,883 Kendall et a1 Mar.29, 1949 g 0 2,505,497Kendall et a1 Apr. 25, 1950 (5,11, 2,734,900 Heseltine Feb. 14, 1956FOREIGN PATENTS 7. The compound represented by the following for-595,784 Great Britain Dec. 16, 1947 mula: 595,785 Great Britain Dec. 16,1947

1. A PROCESS FOR MAKING POLYMETHINE DYES COMPRISING CONDENSING IN THEPRESENCE OF A BASIC CONDENSING AGENT AN INTERMEDIATE SELECTED FROM THOSEREPRESENTED BY THE FOLLOWING GENERAL FORMULA: